This invention relates generally to apparatus and methods for using a shifting tools in drilling wells, and drilling multi-lateral wells. It has special application in near vertical wells, deviated wells, or horizontal wells, and in their completion, re-completion, setting whip stocks, setting premilled window sections, and/or setting other tools down hole where the process of correct orientation of such tools is important. This invention and method applies whether the problem relates to the whole casing string, tubing string, coil tubing string, etc. is required to have some section of it oriented while the rest of the section remains substantially unchanged.
Thus this invention relates to orientation solutions in a well where there is need to orient tools and equipment down hole in a well when either because the tubular walls can not be rotated because of binding tubular material in the well in which it is located or drag and high torque caused by the earth's friction on the tubulars, or just because it makes better economic sense to rotate by using a shifting tool to orient the particular section desired to be orientated while the tubular materials up hole of said shifting tool remain unchanged in their orientation in the well.
In the case of lateral or multi-lateral well drilling, which is on the increase, there are numerous occasions because of the bends in the casing or tubing string or drag and high torque caused by the earth on the tubulars that the up hole portions of said tubular members bind in the hole and they can not be rotated to orient the tools or materials at the desired location by rotating the whole tubular member. In this environment a shifting tool such as this invention has great application.
Since the increase in usage of lateral or multi-lateral well drilling, there has also been an increase in the problems associated with their drilling because they are being used in more and different well conditions and at more extreme angles of deviation from the vertical well bore than ever before. Thus many techniques have been developed to solve some of these problems but only with the result of creating other and different problems, not the least of which is providing a simple and universal assembly and method which can be used for both drilling and completion and also entry and reentry at a later date.
Also many of these solutions are proprietary and they are designed to only be used with other proprietary completion equipment, which is very expensive and specially adapted for use with only one companies equipment. This condition thus leaves many others without a solution to their problems of having a shifting tool for their simple use at a desired location down hole in a well without rotating the whole tubular string or using a complete proprietary system just for the single need to orient particular tools.
Because of the improved drilling technology today, the wells into which premilled window sections may be set can have high angles even in excess of 50 degrees from vertical. Clearly in such environments the earth about the tubular string of pipe would act as a "brake shoe" over a significant portion of the tubular string to the point that the whole string may be impossible to turn for the purpose of rotating the window section into a desired location for the commencement of drilling a lateral well through the window section.
Also in the prior art, because of wells having depths of 10,000 feet or greater today, there is an even greater need for finding the exact orientation of a down hole tool and for having the ability to manipulating them in place. For example in a well having a depth of 10,000 feet, just the spring in the drill string and running tools can have several feet of movement or "slack" between the surface and the down hole section being desired to be manipulated. Also because of this "cork screw" effect and the depth the tubular material is subject to much greater resistance and likelihood of binding in the well bore exist, with the inability to use such tools as junction sections for drilling multi-lateral wells or their loss down hole because the junction section could not be orientated in the desired direction to drill a multi-lateral well.
Also in the prior art there were many complicated shifting tools with many complicated parts in them and they generally remained down hole after their work of shifting and orientation was complete. This created problems in the bore of the tubular materials in which they were used as this reduced the size of the inside diameter of the tubular materials and restricted their creative use for other purposes.
In yet some other prior art shifting tools, there was no way to obtain a positive indication on the surface of when the apparatus was correctly oriented with respect to the lateral or multi-lateral about to be manipulated and then provide a way to lock the shifted tool in place against inadvertent movement.
While other shifting tools in the prior art have been somewhat successful in shifting the tools to be oriented, they have required additional trips into the hole to retrieve them and have driven up the cost of using the shifting tools in the modern market place of today.
Clearly until the use of premilled windows in wells today, there was not as much need to turn the casing down-hole in order to position it in a certain orientation and thus the creation of some of the demand for shifting tools today. The modern problems of multi-lateral drilling through premilled windows have only magnified the need for simple and effective shifting tools because of the torque problems which can prevent the orientation of a premilled window which can result in the premilled window being lost from use and the failure to drill the multi-lateral well or if drilled, only at great additional costs.
For example U.S. Pat. No. 5,615,740 is typical of the prior art in that while it provides for a removable sleeve that is used in the cementing operations, involving a premilled window, the sleeve is used to find the orientation of the premilled window, to allow the cement to pass thru the premilled window during the cementing operations and to provide pressure integrity during the installation of the casing, but does not provide any capability with the system to rotate the casing prior to the cementing operations without rotating the entire casing string. While this would work with casing strings which were capable of being rotated, it would be a complete loss or a great expense if the casing string were not capable of being rotated.
Also in the prior art some tools such as U.S. Pat. No. 5,775,444 were constructed of high strength steel and complicated parts to manipulate such things as drilling motors in a down hole environment and if significant problems developed the tool had to be milled out down hole. Alternatively many of these mechanisms on the inside of the more complicated tools are an integral part of the tool and cannot be removed once the tool is down hole without removing the entire housing. Thus the costs of removal of such tools was significantly increased.